NEW YORK (CNN) -- None of us was there that fateful night when a young man lost his life on his wedding day, the night three New York Police Department detectives lost their careers and lives as they knew them.

But the people who were there told their version of events. And the judge, also sitting as the jury, decided whom to believe. Isn't that the very crux of our judicial system?

I predict that the Sean Bell case will be examined in law school classrooms across the country. It has given us a bird's-eye view into a courtroom practice that many had never heard of: the bench trial.

The Sixth Amendment to the Constitution ensures that we have the right to a trial by a jury of our peers in a serious criminal case. But as with all rights, you can voluntarily, knowingly and intelligently waive that right and instead have your case tried by a judge.

That is what Michael Oliver, Marc Cooper and Gescard Isnora did. Many thought it was a gamble. It was a gamble that paid off.

Justice Arthur Cooperman, a 74-year-old bench veteran, acquitted all three detectives. The public is outraged. But it shouldn't be. Cooperman did what we ask every juror to do: consider and determine the facts of the case -- that is, what he believed to be the true facts -- from among all of the evidence in the case. Watch why the judge didn't believe the prosecution witnesses »

In a criminal trial, jurors are instructed that a defendant does not have to prove his innocence. It is the prosecution that has a very high burden, to prove the charged conduct beyond a reasonable doubt. Jurors are also given specific instructions on how to weigh evidence in every single criminal case. In fact, I've heard it so many times that I can recite it from memory:

As judges of the facts, you alone determine the truthfulness and accuracy of the testimony of each witness. You must decide whether a witness told the truth and was accurate, or instead, testified falsely or was mistaken. You must also decide what importance to give to the testimony you accept as truthful and accurate. It is the quality of the testimony that is controlling, not the number of witnesses who testify. If you find that any witness has intentionally testified falsely as to any material fact, you may disregard that witness's entire testimony.

It is so very clear that Cooperman did exactly what any juror was supposed to do.

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He listened to the evidence. He learned that Club Kalua, the strip club that Sean Bell and his companions were at that night, had been at the center of neighborhood complaints, drug activity and prostitution arrests, which is why undercover officers were there in the first place.

He heard the consistent grand jury testimony of all three defendant police officers. He heard the testimony of Detective Hispolito Sanchez, an undercover officer inside the club who heard Bell's companion, Joseph Guzman say "Yo, get my gun" and heard Sean Bell threaten to beat up a man near an SUV.

And he heard the testimony of Guzman, who denied, contrary to the testimony of other witnesses, that he uttered the words "Go get my gun." Cooperman also learned that Guzman had spent five years in prison for robbery and drug convictions for selling crack and was suing for $50 million in civil court.

It was clear that Guzman was the linchpin of this case. If you believe him, that the officers shot at Bell and his friends for no reason at all, the officers are guilty. If you don't believe him, then his statement -- "Go get my gun" -- sent the night into mayhem, causing the officers to believe that the men were armed and justifying the officers' actions that night.

Guzman was combative on the stand, irreverent. During his cross-examination by attorney Anthony L. Ricco, who represented Isnora, he shot back: "You know what needs to happen? This needs to happen to your family."

In explaining his decision, Cooperman said prosecutors had not proved their case beyond a reasonable doubt because of a combination of factors. Chief among them: inconsistent statements by prosecution witnesses, their demeanor on the stand, their interest in the outcome of the case and their motives to lie.

"These factors," the judge said, "had the effect of eviscerating the credibility of those prosecution witnesses."

Translation: The government could not prove its case against the officers because the judge didn't believe Trent Benefield and Joseph Guzman. They are suing the police department for $50 million. They blew the case for the prosecution.

This is not over. There is a civil case pending, and the standard of proof is much lower. The feds are now looking at it. And we will be watching and deciding what and whom to believe.E-mail to a friend